Compound and double angle formulaeEdexcel A-Level Maths: Mind map

Exam questions on Compound and double angle formulae

1. Angles $A$ and $B$ are acute, with $\sin A=\frac{3}{5}$ and $\cos B=\frac{5}{13}$.
   Find the exact value of $\tan(A+B)$.2 marks
2. The angle $x$ is acute and $\tan x=\frac{3}{4}$.
   Hence find the exact value of $\cos4x$.2 marks
3. Consider the equation $\cos2\theta+3\sin\theta=2$, where $0\le\theta<360^\circ$.
   Show that the equation can be written as $2\sin^2\theta-3\sin\theta+1=0$.3 marks